Receptors

Major nodes: ClassI | OR1/3/7 | OR2/13 | OR2M/T/V | OR4/12 | OR5/8/9 | OR5A/AN | OR6/10/11 | OR10D/G/S | OR14 | OR51/52 | Schiff6

────────────────┬───┬───┬────── OR56B1
                │   │   └────── OR56B2
                │   └────── OR56B4
                └───┬───┬───┬────── OR56A4
                    │   │   └────── OR56A5
                    │   └────── OR56A1
                    └────── OR56A3